Power bank charging system



FIG. 1 is a front perspective view of a power bank charging system showing our new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines in the figures depict portions of the article which form no part of the claimed design. 

CLAIM The ornamental design for the power bank charging system, as shown and described. 